Heretofore, a fuel cell has been known which supplies fuel gas (for example, hydrogen) to a fuel electrode (anode), and supplies oxidizing gas (for example, air) to an oxidizing electrode (cathode), thereby electrochemically reacting these gases with each other to generate electric power. In this type of fuel cell, discharge gas from the fuel electrode side is circulated to a fuel gas supply side by a circulation pump and the like, and thus reaction efficiency is enhanced.
Incidentally, in this fuel cell water is generated following the reactions of the gases on the fuel electrode and the oxidizing electrode. Generated water is particularly prone to be generated on the oxidizing electrode side. The generated water flows into a circulation system of the fuel gas, since the generated water moves toward the fuel electrode side through an electrolyte membrane. The generated water may cause a malfunction in the circulation means such as the circulation pump. Furthermore, the generated water flows into the fuel cell, and a problem of flooding can occur which will decrease the reacting area of the fuel electrode. Therefore, a gas/liquid separator may be provided in the fuel gas circulation system to separate the circulated gas (the discharge gas from the fuel electrode) into the fuel gas and the water (for example, refer to Patent Literature 1).    Patent Literature 1: Japanese Patent Laid-Open Publication No. 2003-311185